Detachable security lock for hinged doors



Nov. 19, 1968 D. c. CARVER DETACHABLE SECURITY LOOK FOR HINGED DOORS Filed March 1, 1967 INVENTOR. DONALD C. CARVER BY MAHONEY, MILLER 8 RAMBO 4 'AWML TTOHNEYS United States Patent 3,411,817 DETACHABLE SECURITY LOCK FOR HINGED DOORS Donald C. Carver, Columbus, Ohio; Geraldine B.

Carver, executrix of the estate of said Donald C.

Carver, deceased Filed Mar. 1, 1967, Ser. No. 619,827 2 Claims. (Cl. 292-298) ABSTRACT OF THE DISCLOSURE My invention relates to a simple lightweight security lock structure which can be readily carried by a person from one room to another and which can be easily and quickly mounted on the jamb of a door of that room which is hinged for swinging inwardly. The lock is very sturdy and rugged and when mounted on the door jamb in association with the usual keeper plate of the ordinary spring type door latch or look can permit the door to swing into closed position and can then be readily adjusted into locking engagement with the door to maintain it closed even though a person opens an ordinary lock on the door with a key. To permit opening of the door, my lock can be adjusted readily into a non-engaging position from inside the room and when leaving the room, the lock can be detached from the door jamb and carried in the pocket or purse of the person.

In the accompanying drawing, I have illustrated a preferred embodiment of my invention and in this drawing:

FIGURE 1 is a top elevational view of the lock showing it in locking position with a door, the door and asso ciated jamb being shown schematically.

FIGURE 2 is an elevational view of the lock taken from the position indicated at line 22 of FIGURE 1.

FIGURE 3 is a top plan diagrammatic view of the lock showing how it can be adjusted to cooperate with doors of varying thicknesses.

FIGURE 4 is a perspective view showing the two units of the lock ready for assembly.

FIGURE 5 shows the two units arranged flat together for positioning in the pocket.

With reference to the details of the drawing, my lock is adapted to be positioned in the vertical crack C between the free edge of a hinged door D that fits within the jamb J. Along this edge at a suitable level there is usually provided a latch keeper plate K with a socket S formed therein and sometimes formed in the material of the jamb inside the plate. The socket S always has a straight vertical edge E on its inner side that is the side toward the inner side of the door in which direction the door is hinged to swing. The socket S usually receives the spring latch or bolt on the latch or look unit L ordinarily provided on the door.

The lock of my invention comprises a jamb-engaging mounting unit and a separate door engaging abutment and bracing unit 11 which are clearly shown separated in FIGURE 4. Both of these units are preferably made of hardened steel of a suitable gauge and preferably of stainless steel.

The mounting unit 10 is formed as a flat elongated plate 12 which is relatively thin and of suitable Width. At one end it is provided with an integral attaching and anchoring flange 13 which is bent at substantially a right angle to the plane of the main part of the plate 12. The flange extends the greater portion of the Width of the plate 12 and for the remainder of its width, at this end there is an integral outwardly extending tang 14. The tang 14 projects outwardly longitudinally from the end of the plate 12 for a substantial distance. Instead of the Patented Nov. 19, 1968 tang 14 being at one longitudinal edge only, another (not shown) could be at the other edge with the flange 13 positioned laterally therebetween. However, it is important that the flange 13 be of substantial lateral extent for strengh.

Substantially midway of the main part of the plate 12 is a small centrally located opening 15 and spaced longitudinally in one direction of this opening is a set 16 of transversely extending receiving slots and longitudinally in the opposite direction is a set 17 of transversely extending slots. Each set of slots is shown as comprising three slots which are disposed parallel with each other but the number of slot can be varied. The opening 15 merely serves to readily indicate the separation of the two sets of slots and it is important that the slots in the respective sets be spaced uniformly and that the number in each set is the same.

The other unit 11 is composed of two parts, namely, a door-engaging abutment plate 20 and a bracing plate 21. The plates 20 and 21 are of less width than the plate 12 being slightly less in width than the l ngth of each of the slots of the sets 16 and 17. The plate 20 is of a selected length somewhat shorter than the plate 21 and the latter plate is somewhat shorter than the mounting plate 12. The plate 20 is hinged at one end to an end of the plate 21 by a transverse hinge 22 which permits the two plates to fold toward each other in the direction of the arrow of FIGURE 4 even into engagement as indicated in FIGURE 5. The outer free end of the plate 20 is provided with an integral tongue 23 which is at an angle of approximately 45 to the main part of the plate 20. Similarly, the outer free end of the plate 21 is provided with an integral tongue 24 which is at an angle of approximately 45 to the main part of the plate and is of slightly greater extent than the tongue 23.

In the use of this lock, assuming a person is'inside a room where the door D swings inwardly, he mounts the lock on the door jamb by taking the separate plate unit 10, disposing it vertically on edge in fiat contact with the jamb and with the attaching flange 13 extending into the socket S and engaging the edge E of the socket S at the inner side, as shown in FIGURE 1. The tang 14 will project inwardly farther beyond the flange 13 and will be at a right angle to the flange and in the same vertical plane as the main part of the plate 12. The door D may then be swung closed with its edge cooperating with the jamb to provide the vertical crack C in which the plate 12 is disposed. The plate 12 will extend from the crack C inwardly beyond the inner surface of the door and substantially normal thereto. Then the unit 11 is mounted thereon in locking engagement with the door to prevent inward swinging thereof. To mount the unit 11 on the unit 10, the unit 11 is disposed upright with the tongues 23 and 24 thereof directed toward the face of the plate 12 at the side toward the edge of the door D. The tongue 23 is slipped into the upright slot of the inner set 16 which is closest to the face of the door and is exposed. Then the plate 21 is swung toward the plate 20 and the tongue 24 is snapped into the upright slot of the outer set 17 which is in the same .position in this set as the one of the set 16 in which the tongue 23 was previously inserted. The tongue 23 will be dis-posed substantially at a 45 angle relative to the plate 12 after insertion into the slot but the tongue 24 will be at almost a right angle to the plate 12 during its insertion and after insertion in its receiving slot so as to facilitate insertion and withdrawal, as indicated in FIGURE 3. The corresponding slots of the two respective sets 16 and 17 are disposed at such a distance apart that an abutment and bracing structure of right-triangular form is produced, as indicated in FIGURES l and 3. The long or connecting side of the right triangle is formed by a length of the plate 12, corresponding to the distance between the two engaged slots, the short or abutment side is formed by the plate 20, and the bracing or hypotenuse side is formed by the plate 21. For different thicknesses of doors, the position of the tongue 23 in the set of inner slots 16 will be changed and the tongue 24 will be positioned in the corresponding slot of the set 17.

When mounted on the door and jamb in this manner, a right triangular locking structure is produced which includes the plate 20 that forms a locking abutment of substantial extent projecting inwardly from the door jamb and over the inner face of the door D. Regardless of variations in thickness of the door, a pair of slots may be selected readily so that the abutment plate 20 is in firm contact with the inner face of the door D, as indicated in FIGURE 1. The hypotenuse plate or bracing plate 21 firmly braces the plate 20 against the door. There will be no inward yielding of the door under pressure since it will be resisted by the strength of the triangular structure which will be considerable due to the well-known action of a right-triangular structure. The plate 20 will always be at a right angle to the plate 12 which will be anchored to the door jamb by the rugged anchoring flange 13. Rocking of the outer end of the plate 12 about the flange 13 as a fulcrum toward the jamb I will be precluded even if the crack C is considerable, because the tang 14 extends inwardly beyond the flange and will prevent this rocking which otherwise might withdraw the flange from the socket S. Thus, even if a person has a key for the usual lock L on the door, he will not be able to swing the door inwardly if the unit 11 is properly mounted on the unit which, in turn, is properly mounted on the jamb J between the edge of the door and the jamb. Any pressure on the outside of the door will merely cause the tongue 24 to more firmly enter its receiving slot since, as indicated in FIGURE 3, it will be angled relative to the plate 12 slightly toward the door jamb J. However, it can be readily withdrawn from the slot to detach the lock and permit opening of the door. Then the plates 20 and 21 of the unit 11 can be folded substantially flat together and the unit 11 positioned flat on the unit 10, as shown in FIGURE 5, for insertion in a pocket or purse. At this time the tongue 23 will contact the adjacent face of the plate 21 and the extremity of the tongue 24, projecting slightly beyond the plate 20, may be positioned in one of the slots of the sets 16 or 17.

Many advantages of my lock structure have been discussed above and others will be apparent.

Having thus described my invention, what I claim is:

1. A detachable security lock for doors adapted to be mounted in association with the adjacent edge and jamb of a door mounted for inward swinging movement comprising a mounting plate of relatively fiat elongated form adapted to be positioned in the crack between the door jamb and the edge of the door in cooperation with the latch keeper plate on the door jamb, an anchoring flange at an inner end of said plate at substantially a sharp angle for extending into the socket of the keeper plate, a tang on said plate extending beyond said flange as an extension on said plate in the plane thereof, a door engaging abutment plate and a brace plate hinged together for relative swinging and each having a free outer end with a tongue formed thereon at an angle thereto with the tongues extending inwardly from the planes of the plates, said mounting plate having openings for receiving the respective tongues and spaced so that when the tongues are inserted therein, the hinged plates cooperate with the mounting plate to form a substantially right triangular bracing structure with the abutment plate extending outwardly at a right angle to the mounting plate for extending over the inner face of the door, and the bracing plate extending angularly as the hypotenuse between the bracing plate and the mounting plate, said flange being integral with the mounting plate and being bent substantially at a right angle thereto, at least one tang being provided and together with the flange extending the full transverse width of the plate, each of said tongues being integral with its respective plate and bent substantially 45 relative thereto.

2. A detachable security lock for doors according to claim 1 in which each of said openings is in the form of a transverse slot in the plate, said slots being divided into two sets of uniformly spaced slots located at opposite sides of the mid point of the mounting plate, the slots of one set being equal in number and identically spaced to the slots of the other set.

References Cited UNITED STATES PATENTS 908,763 l/l909 Dunn 292298 913,223 2/1909 Minderlein 292293 1,300,481 4/1919 Peterson 292297 2,461,398 2/1949 Sands 292297 MARVIN A. CHAMPION, Primary Examiner.

E. J. MCCARTHY, Assistant Examiner. 

